As youths, the members of The Beatles were enthusiastic followers of Elvis Presley. They recorded a number of Presley covers at " Abbey Road " studios, and although these were not released officially until after the group split, bootleg copies have existed since the late 1960s. In interviews over the years, one or the other of The Beatles has stated that if there had not been Elvis Presley, there probably would not have been The Beatles.

British rock-and-rollers, notably Cliff Richard and The Shadows, were an obvious early influence, especially the trend of adopting a band "look." In their early days as performers, the band took some cues from local Liverpool favourites Rory Storm and the Hurricanes, who Starr had played with prior to joining The Beatles.

George Harrison had a fondness for American rockabilly music, particularly that of Eddie Cochran and Carl Perkins. The band's early stage shows featured several Perkins tunes; some of these (notably Honey Don't, featuring an early Starr vocal) they eventually recorded for their albums. Harrison 's guitar work remained highly influenced by rockabilly styles throughout the band's tenure.

While many of these American influences drew from the blues music form, The Beatles, unlike their contemporaries The Rolling Stones, were seldom directly influenced by the blues. Drawing inspiration from an eclectic variety of sources, their home idiom was closer to pop music (during their early fame they were sometimes referred to as a "mod" band, a label they seem to have resisted).

The Beatles were also fond of Little Richard and some of their songs (especially in their early repertoire) featured falsetto calls similar to his, most notably on McCartney's rendition of his song Long Tall Sally. In 1962 Richard socialised with The Beatles around Hamburg and they performed together at the Star-Club. Long Tall Sally became a permanent fixture in The Beatles' concert performances.

The Everly Brothers were another influence. Lennon and McCartney consciously copied Don and Phil Everly's distinctive two-part harmonies. Their vocals on Love Me Do and Please Please Me were inspired by the Everlys' powerful vocal innovation on Cathy's Clown (1960), the first recording to ever reach number one simultaneously in the USA and England . Two of Us, the opening track on Let It Be is overtly composed in the Everly style and McCartney acknowledges this in the recording with a spoken Take it Phil. McCartney later namechecked 'Phil and Don' in his solo track, Let Em In.

The song-writing of Gerry Goffin and Carole King was yet another influence. Some say that one of The Beatles' many achievements was to marry the relative sophistication of Goffin and King's songs (which used major-seventhchords, for example) with the straightforwardness of Buddy Holly, Berry and the early rock-and-roll performers.

With You've Got to Hide Your Love Away (Help!) and Norwegian Wood (This Bird Has Flown) (Rubber Soul) from 1965, Lennon began to show a heavy Bob Dylan influence. Lennon is said to have been stunned by Subterranean Homesick Blues, and wondered how he could ever outdo it. He started exploring more complex topics and lyrics and incorporated "folkier" musical styles in some of his songs. And perhaps as a sign of respect, Lennon stopped playing harmonica when Dylan became iconically associated with the instrument. The growing complexity of the group's lyrics after 1965 owe much to Dylan.

Paul McCartney is usually cast as the group's romantic balladeer, and he displays a singular ear for melody and an arguably unrivalled facility for writing classic pop songs in a wide range of genres, ranking alongside Irving Berlin, Cole Porter and the Gershwin brothers as one of the greatest popular song writers of the 20th century. However, in recent years since the deaths of Lennon and Harrison, he has insisted in a number of media interviews that he was far more involved in the London avant garde scene than was Lennon, and that he was in some respects the more "experimental" of the two.

McCartney retained his affection for the driving R&B of Little Richard in a series of songs Lennon dubbed "potboilers", from I Saw Her Standing There (1963) to Lady Madonna (1968). Helter Skelter (1968), arguably an early heavy metal song, is also a McCartney composition. McCartney's lyrical style evolved a more detached, literary stance than in the increasingly personal and confessional work of Lennon, and Lennon was reported to have become more critical of McCartney's writing in the mid-Sixties.

George Harrison derived his early guitar style from 1950s rockabilly figures such as Carl Perkins, Scotty Moore (who worked with Elvis Presley) and Duane Eddy, but his single biggest influence as a guitarist came from country guitar legend Chet Atkins. All My Loving (1963) and She's a Woman (1964) are prime examples of Harrison 's early rockabilly-influenced guitar work.

Harrison retained Western musical forms in his later compositions, emerging as a significant pop composer in his own right, although occasionally reprising major themes indicating his relationship with Hindustani music and the Hindu god Krishna. His later guitar style, while not displaying the virtuosity of Jimi Hendrix or Eric Clapton, was distinctive with its use of clear melodic lines and subtle fills as in Something (1969) and Let It Be (1970), contrasting with the increasingly distorted riffs and rapid-fire guitar solo work of his contemporaries.

Ringo rarely wrote songs, but he possessed a gentle, somewhat comic baritone; his best-known vocal performances are Yellow Submarine (1966), With A Little Help From My Friends (1967) and Octopus's Garden (1969). In addition to his skilled (and arguably underrated) drumming and his comical everyman image, he was also a considerable influence on Lennon's songwriting due to his quirky and often amusing turns of phrase. Three of these were immortalised in the songs A Hard Day's Night, Eight Days A Week and Tomorrow Never Knows. As evidenced by his Beatles vocal performance on Help! (their cover of Buck Owens' Act Naturally), Starr was a dedicated country music fan and was largely responsible for the group's occasional forays into the genre in songs such as What Goes On (1965) and Don't Pass Me By (1968).

Later Beatles material shifted away from dance music and the pace of the songs is often more moderate, with interest tending to come from melody and harmonic texture rather than the rhythm (Penny Lane from 1967 is an example). Throughout their career The Beatles' songs were rarely riff (or ostinato)-driven; Day Tripper (1965) and Hey Bulldog (1969, recorded 1968) are among the notable exceptions.

The decision to stop touring in 1966 caused an abrupt change in musical direction. Reportedly stung by criticism of Paperback Writer, The Beatles poured their creative energies into the recording studio. They had already shown a clear trend towards progressively greater complexity in technique and style but this accelerated noticeably in their Revolver album. The subject matter of the post-touring songs branched out as well, as all manner of subjects were introduced, from home repair and circuses to nonsense songs and others defying description.

The extreme complexity of Sgt. Pepper's reached its height on the Yellow Submarine soundtrack album, parts of which (for example It's All Too Much and Only a Northern Song) were left over from 1967 and were apparently used because The Beatles themselves weren't much interested in the animated film as a project and weren't inclined to exert themselves by producing much new material for it.

After the Revolver/Sgt. Pepper's phase, came the double LP The Beatles, known to most as The White Album because of its plain white sleeve. Partly written in India, it involved some simpler subjects (for example "Birthday"), and some of the songs (for example "Why Don't We Do It in the Road?" and "Wild Honey Pie") were far less complex than their material of just a year or two before. In 1969, the band became less united during sessions for the aborted Get Back project (which eventually emerged in 1970, much altered, as Let It Be). This had been intended as a return to more basic songs and an avoidance of thorough editing or otherwise "artificial" influences on the final output. Ironically Let It Be was heavily overdubbed and edited by producer Phil Spector in his wall of sound technique. With Get Back behind them, George Martin was asked to produce the last album The Beatles recorded, Abbey Road, representing a mature attempt to integrate what they knew and use recording studio techniques to improve the songs rather than experiment to see what happened.

For many, the group's musical appeal lay in the interaction of Lennon and McCartney's voices and musical styles. It is sometimes said they not only supplied missing bits and pieces for each other's songs, but shared a competitive edge that brought out the best in both. Harrison 's lead guitar and vocals along with Starr's understated and faithful drumming contributed their own chemistry. Finally, The Beatles' stage presence and charm as a group kindled their live shows, as well as relationships with key people in their careers. After the group dissolved some critics cited their solo releases as a demonstration of how important this group collaboration had been.